Field
The present invention relates to a manufacturing method of a semiconductor laser device that uses a single crystal SiC as a submount.
Description of the Related Art
In a manufacturing method of a silicon carbide (SiC) single crystal described in Japanese Patent Application Laid-open No. 2000-34199 (hereinafter, also referred to as a “conventional manufacturing method”), a coating material made of a metal material is formed on one surface of a SiC substrate including a micropipe. In this method, the micropipe is closed such that the coating material is formed by using a chemical vapor deposition (CVD) method, a sputter vapor deposition method, or the like and then a heat treatment is performed (for example, refer to paragraphs 14 and 15).
However, the conventional manufacturing method uses a heat treatment which requires a long period of time. In addition, even with the use of the coating material made of a metal material, a micropipe with a large diameter may be left in a penetrating state without being completely closed. In Japanese Patent Application Laid-open No. 2000-34199, a SiC substrate is used as a substrate for epitaxial growth. Using the SiC substrate in Japanese Patent Application Laid-open No. 2000-34199 as a submount on which a semiconductor laser element is to be mounted may possibly result in penetration by a conductive member such as a eutectic solder into the micropipe. In this case, an insulating property of the single crystal SiC is destroyed and the semiconductor laser device using the single crystal SiC becomes defective.
The present invention is devised to provide a submount capable of reliably closing the micropipe to restraining a decline in insulating property attributable to a micropipe, a manufacturing method of the submount, a semiconductor laser device using a single crystal SiC as a submount, and a manufacturing method of the semiconductor laser device.